var arrs = [1, 2, 3, 4, 5, 6];

//传统for循环
for (let i = 0; i < arrs.length; i++) {
    console.log(arrs[i]);
}

//for...in循环
for (key in arrs) {
    console.log(arrs[key]);
}

//for...of循环
for (value of arrs) {
    console.log(value);
}
